The object of this invention is a method and apparatus for recording information from a slidable sheet of a reusable image media (RIM) cassette, in which the information on the sheet surface drawn out of the cassette is read with the aid of a beam directed on it and the sheet is emptied of information after the reading and returned to the cassette.
There are materials which have the ability to be tuned by the effects of radiation, such as x-ray, ultraviolet or gamma radiation directed on them. The absorbable radiation energy may include information which can be read with the aid of secondary radiation, such as a laser beam on the visible light region which is directed onto the material, by recovering the light emitted from the material and by converting it to an image. This RIM technique is based on x-ray photography in which radiation, conducted through the photographed object and modified by the absorption which occurs in the object, is focused on a layer of phosphor on the sheet which is to be excited. The phosphor layer records the information included in the beam and the sheet which is exposed in this way is read by a laser beam in order to form an image on a light multiplier or film.
It is possible to form the X-ray image directly with the aid of a reading head for the sheets connected to and in conjunction with the photographing device. On the other hand, it is possible to enclose the sheet in the cassette after the exposure and to carry out the reading later by a separate reading device. The latter technique, which the present invention relates to, is more flexible because the reading of the sheet enclosed in the cassette is not bound by time or place to the photographing procedure.
The reading of the sheet in the cassette has so far been effected in such a way that the sheet has been drawn out of the cassette onto a belt conveyor and the information on the sheet has been read in the reading position with the conveyor moving. In order to achieve a successful reading, the linear movement of the conveyor must be as smooth as possible. After the reading, the sheet has been emptied of information with the aid of a powerful light on the path of the conveyor in a subsequent emptying position. After the emptying the sheet has been returned to the cassette to wait for the next operation.